A radio access system such as a mobile telephone system and a wireless LAN (Local Area Network) is widely used today. Also, in the field of radio communication, next generation communication technology is continuously being discussed in order to further improve a communication speed and a communication capacity. For example, in the 3GPP (3rd Generation Partnership Project), which is an association for standardization, the standardization of a communication standard called LTE (Long Term Evolution) and the standardization of a communication standard called LTE-A (LTE-Advanced) are completed or currently under study.
In such a radio communication system, there is a case when a base station apparatus distributes information in broadcast to all terminal apparatuses which are existent in the coverage of the self-station. As such a distribution system, there are an ETWS (Earthquake and Tsunami Warning System) and a CMAS (Commercial Mobile Alert System), for example.
The ETWS is, for example, a system which distributes highly urgent information of a tsunami, an earthquake, etc. to a terminal apparatus. Also, the CMAS is, for example, a system which distributes wide information such as a presidential message, an advertisement of a commercial product to a terminal apparatus.
In regard to the ETWS and the CMAS, the base station apparatus receives from an MME (Mobile Management Entity) a “WRITE-REPLACE WARNING REQUEST” (which may hereafter be referred to as an “S1AP: WRITE-REPLACE WARNING REQUEST”), that is, an S1 Application Protocol (S1AP) Message. Taking the opportunity of receiving the message concerned, the base station apparatus distributes the message to the terminal apparatus. In this case, there is also a case that there exists an upper-level apparatus which instructs the MME to transmit the “S1AP: WRITE-REPLACE WARNING REQUEST” to the base station apparatus.
FIG. 16A illustrates an example of parameters (or IE: Information Elements) which are included in the “S1AP: WRITE-REPLACE WARNING REQUEST”. The “S1AP: WRITE-REPLACE WARNING REQUEST” includes each parameter of “Message Identifier”, “Serial Number”, “Repetition Period”, “Number of Broadcasts Requested”, “warning type” and “Warning Message Contents”.
The “Message Identifier” and the “Serial Number” represent identifiers which identify, for example, a message content. The “Message Identifier” and the “Serial Number” are used, for example, in a radio section also, so that the terminal apparatus can confirm the duplicated reception etc. of a message using the above two parameters.
The “Repetition Period” denotes a transmission period of the message content, for example. Also, the “Number of Broadcasts Requested” denotes the number of transmission times of the message content, for example.
The “warning type” denotes a disaster type, for example, which is a parameter included in the ETWS, whereas the parameter is not included in the CMAS. In the “Warning Message Contents”, a message content is included, for example.
The base station apparatus receives the “S1AP: WRITE-REPLACE WARNING REQUEST” from the MME, to distribute the message content included in the “S1AP: WRITE-REPLACE WARNING REQUEST” to the terminal apparatus.
For example, the base station apparatus distributes the message content using SI (System Information) which is notification information. In SI, ten or more SIB types (System Information Block types) are defined. In the ETWS, an SIB10 and an SIB11 are used. For example, the base station apparatus first distributes the SIB10 to notify the terminal apparatus of the advent of a disaster, and then distributes the SIB11 to transmit concrete information of the disaster. On the other hand, in the CMAS, a single SIB12 type is used.
Examples of parameters included in the SIB10, the SIB11 and the SIB12 are depicted in FIG. 16B, FIG. 17A and FIG. 17B, respectively.
In the SIB10, “messageIdentifier”, “serialNumber” and “warningType” are included.
The “messageIdentifier” and the “serialNumber” correspond to the “Message Identifier” and the “Serial Number” in the “S1AP: WRITE-REPLACE WARNING REQUEST”, respectively, so as to represent each identifier to identify the message content.
The “warningType” corresponds to the “warning type” in the “S1AP: WRITE-REPLACE WARNING REQUEST” to represent a disaster type.
In the SIB11, “messageIdentifier”, “serialNumber”, “warningMessageSegmentType”, “warningMessageSegmentNumber” and “warningMessageSegment” are included.
In the “messageIdentifier” and the “serialNumber”, the same information as the “messageIdentifier” and the “serialNumber” in SIB10 is included, respectively.
In the base station apparatus, for example, a message content included in the “Warning Message Contents” of “S1AP: WRITE-REPLACE WARNING REQUEST” is divided into each segment of a size that can be transmitted to the terminal apparatus. Then in the base station apparatus, each divided segment is transmitted through each SIB11.
The “warningMessageSegmentType” represents an identifier indicating the last segment of the divided message, for example. Also, the “warningMessageSegmentType” represents, for example, the number of each divided message. Further, the “warningMessageSegment” represents, for example, a message content. Based on the above parameters, for example, the terminal apparatus unifies the segments to reproduce a message.
The SIB12 includes, for example, parameters equivalent to the SIB11. An “r9” included in the parameter represents Release 9.
With regard to timing in which the base station apparatus transmits each SIB after an SIB3, the timing is specified by “SchedulingInfo” which is included in an SIB1. The “SchedulingInfo” is notified from the base station apparatus to the terminal apparatus. The terminal apparatus waits for each SIB at timing specified by the “SchedulingInfo”.
FIG. 18 illustrates an example of setting parameters of “SchedulingInfo” included in the SIB1. The “SchedulingInfo” includes two parameters which are “si-Periodicity” and “SIB-MappingInfo”.
By the “si-Periodicity”, for example, an SIB transmission period is designated on the basis of each radio frame (1 radio frame=10 subframe=0.01 second). Also, by the “SIB-MappingInfo”, for example, there is designated an SIB type which is to be transmitted at a period designated by the “si-Periodicity”. As depicted in FIG. 18, the transmission period of each SIB can be set from among a plurality of transmission periods.
Additionally, there is a difference between a value of “Repetition Period” in the “S1AP: WRITE-REPLACE WARNING REQUEST” which the base station apparatus receives from the MME and a value of the “si-Periodicity” included in the “SchedulingInfo” which the base station apparatus transmits to the terminal apparatus. For example, the “Repetition Period” is a message transmission period of which unit is a second. On the other hand, the “si-Periodicity” is an SIB transmission period of which unit is a radio frame.